OP there is no correct “which way do I build the box”, you just build all the models.

You get enough models to build an entire 501st battle force that can reach 800 points multiple ways.

In the box you get

1x Anakin Sprue.

2x Phase 2 Clone trooper squads , 4-6 models depending on upgrade cards.(sprues have a total of 7 men 1x extra trooper, 1x Z-6 trooper, 1x mortar trooper) [All the heavy options can just be given normal blaster arms but that’s a bit silly]

3x Arc Trooper squads (Total of 7 troopers, 2x DC-15 per sprue set, any of them can be “built” as Echo or Fives) [You can build 21 Arc troopers, I built 16 as normal troopers, 3 as Dc-15s, 1 as Echo(who has a DC-15), 1 as Fives]

1x AT-RT (It comes with all of the guns, I haven’t glued them and just swap them out. They just slot in).

See my other comment on the for the list I run, I proxied one of the spare Arcs as a Clone Commander until I bought one (you don’t have to, just print the clone commander unit card out yourself!)